I don't have any issue with the service delta airline provides, be it within usa or international. Delta airline is good for flying short distance but not so much long distance.
I flew from rdu to france for 8 hrs and i did not enjoy their flight at all. The seats are very small with very little room for leg space and i am 5ft 2in in height. Since i had delta membership i chose this airline. But i am already looking for other options for international travel. This was my first experience with delta on international flight.
I have flown with other airlines internationally in economy class but none were this much uncomfortable as delta.
Even the connecting flight delta arranged for from france to India, "Air France" was good.